The present invention relates to an antiskid control system for the fluid pressure brakes of a wheeled vehicle, particularly a road vehicle, wherein one wheel of at least one axle is provided with a sensor for detecting the dynamic wheel behavior during braking so as to reduce, hold constant or increase the wheel brake pressure in accordance with operation of a modulator valve assembly consisting of solenoid operated supply and exhaust valves controlled by an electric evaluation circuit that is subject to output signals from the wheel sensor.
Wheel antiskid control systems of the above type are theoretically comparable in effectiveness to systems in which each wheel is provided with a separate control channel and have the advantage of being considerably less expensive in that only half as many components are required.
In actual practice, however, the effective brake forces on the sensed and non-sensed wheels may differ due to variables in the brake shoe linings and force transmitting devices in spite of the application of uniform brake pressure to the respective wheels, thus giving rise to instability of the non-sensed wheel and possible locking thereof when the sensed wheel is free of skidding such that the skidding condition of the non-sensed wheel is undetected.